By definition, the term “dry cleaning” has been used to describe processes for cleaning textiles using non-aqueous solvents. Dry cleaning is an old art with solvent cleaning first being recorded in the United Kingdom in the 1860s. Typically, dry cleaning processes are used with delicate fabrics such as wool and silk which are subject to shrinkage in aqueous laundering baths, or which are judged to be too valuable or delicate to be subjected to aqueous laundering processes. Such garments usually have a tag affixed to them either identifying the garment as “dry clean only” or providing some other appropriate laundering tocsin. For the last fifty years, the most widely-used non-aqueous solvent of choice for commercial dry-cleaning has been perchloroethylene.
While perchloroethylene is superior to the non-aqueous solvents that it replaced, it has several disadvantages. In particular perchloroethylene has been identified as a hazardous air pollutant by the U.S. Environmental Protection Agency and has been long associated with nervous-system and kidney disorders among industrial workers. In 1995, the Environmental Protection Agency classified perchloroethylene as a “probable human carcinogen.” Perchloroethylene's potential carcinogenic effects are not limited solely to industrial workers or those who operate perchloroethylene-based dry clean processes: a recent study of commercial dry cleaners in New York revealed that many of these cleaners used such high amounts of perchloroethylene to clean garments, that customers who wore freshly dry-cleaned garments could inhale enough perchloroethylene to incur a slightly increased risk of cancer. As a consequence of the hazardous nature of perchloroethylene, dry cleaning processes utilizing perchloroethylene must be done at commercial establishments. Not only is this both inconvenient and expensive, but it can expose delicate and often expensive garments to dry-cleaning processes of inconsistent quality and garment care. Many consumers who have taken their goods to a commercial dry-cleaner have reported them being damaged either by excessive shrinking, discoloration or tearing. The use of perchloroethylene in commercial dry-cleaning establishments also tends to leave a “chemical” smell on clothing that consumers find unsatisfactory.
Moreover, while solvent-based dry cleaning processes are quite effective for removing oily soils and stains, they are not optimal for removing particulates such as clay soils, and may require special treatment conditions to remove proteinaceous stains.
Given the foregoing, there is a continuing need for a method or process that provides excellent cleaning benefits on a variety of stains and soiling conditions and imparts a “fresh” and “clean” scent to delicate or dry-clean only goods without the use of hazardous or harmful chemicals and which provides excellent cleaning benefits on a variety of stains and soiling conditions. Accordingly, it is a feature of the present invention to provide a process for cleaning delicate or dry-clean only garments that uses non-toxic and non-hazardous chemicals to provide superior cleaning benefits on a wide variety of soils and stains. Such a method or process should also be relatively convenient and inexpensive and be without the possible garment damage and adverse “chemical” scent that is sometimes the result of commercial dry-cleaning.
Ideally, particulates and proteinaceous stains, as well as oily soils and stains, are removed from fabrics using detersive ingredients and under operating conditions which are more akin to aqueous laundering processes than to conventional dry cleaning. Such aqueous laundry processes also consistently impart a “freshness” or “clean” scent to fabric, rather than the “chemical” smell that is often found when perchloroethylene or other non-aqueous solvents are used.
Perhaps the most widely practiced aqueous laundering process is that which the consumer performs when she or he immerses a garment into an aqueous laundry detergent solution in a conventional home washing machine. Such a process has long been shown to provide excellent performance for both stain removal and overall garment cleaning and can be performed without using hazardous or toxic chemicals. Moreover, the use of an aqueous laundering process in a conventional washing machine is considerably more convenient and inexpensive than virtually any other laundering method.
Nonetheless, such processes can produce unacceptable results when applied to a broad range of delicate or dry-clean only garments, such as those made from wool. Wool, is made up of fibers which can interlock with one another by a series of “scales”. Generally, these interlocking scales cannot move past one another and as a result wool is a relatively strong textile. However, when wool becomes wet or moistened, the fibers move together, and the wool garment shrinks. This shrinkage cannot be undone because these “scales” can only move past one another in a preferred direction. Sufficient force cannot be exerted to move them in the direction opposite to the preferred direction to undo the shrinkage. Thus when the wool garment is removed from the aqueous laundry process, shrinkage has occurred and the garment is irreversibly damaged. Similarly, rayon, when saturated with water, becomes extremely weak and the subsequent agitation and abrasion that it experiences in a typical aqueous laundry process is likely not only to cause severe damage to the garment but also to leave it extremely wrinkled. Similarly, delicate fabrics like silk will not only be severely wrinkled but also may lose their desirable soft feel.
Garments such as silks are also vulnerable not only to the mechanical agitation of a conventional washing machine but are also particularly vulnerable to the typical laundry detergents because such detergents may contain ingredients that are too harsh for such delicate fabrics. It is thus desirable to provide an aqueous laundering process adapted for use in a conventional washing machine that is not harmful to garments made from fabrics such as wool, leather, suede, rayon, silk, acrylics, triacetates, fine cottons and blends of these aforementioned materials.
Therefore, a need exists for a process for laundering delicate or dry-clean only garments in a washing machine without the deleterious consequences described above. A need also exists for a convenient, inexpensive, and efficacious way to clean delicate and dry-clean only garments in the home.